1. Field of the Invention
The present invention relates to a power consumption control device, a timepiece device, an electronic device, a power consumption control method, and a power consumption control program.
2. Background Art
A circuit configuration of a timepiece (timepiece device) including a photovoltaic cell, in which a photovoltaic cell is directly connected to a secondary battery and a timepiece circuit through a backflow prevention diode, and a constant voltage holding circuit regulates the maximum charge voltage of the secondary battery is disclosed (for example, see FIG. 1 of JP-A-60-1587).
However, in the timepiece (timepiece device) disclosed in JP-A-60-1587, even when the secondary battery (secondary power supply unit) is consumed up to an operation limit voltage or lower of a time motor that moves the hands, an operation (clock operation) of driving the time motor is continued. Thus, in this timepiece, the secondary battery enters into an over-discharged state. When the secondary battery enters into an over-discharged state, there is a problem in that the time motor is unable to start moving the hands quickly even if the photovoltaic cell (primary power supply unit) starts generating electricity. This is because it takes time to charge the secondary battery up to the operational voltage of the time motor. Thus, the user has to wait until the secondary battery is charged sufficiently to the operational voltage of the time motor, thus deteriorating convenience.
To obviate this inconvenience, a timepiece in which an operation of charging a secondary battery with a photovoltaic cell and an operation (clock operation of measuring time) of moving the hands by a time motor are controlled in a time-division multiplexed manner is known. However, this timepiece enables the motor to perform the hand movement operation immediately even when the secondary battery enters into an over-discharged state but does not solve the inconvenience caused by a charging standby state, which is to be solved by the present invention. Moreover, the time-division multiplexing of the charging of the secondary battery and the hand movement operation by the time motor results in a decrease in the charging efficiency. As a result, the time for a sufficient charging state is prolonged, thus deteriorating convenience.